Next generation semiconductor memory devices (such as a ferroelectric random access memory (FRAM), a magnetic random access memory (MRAM), and a phase-change random access memory (PRAM)) have been developed in view of achieving high performance and low power consumption. Materials constituting the next generation semiconductor memory devices may have resistance values that change depending on a current and a voltage, and may have non-volatile properties that are maintained even if the current or the voltage is interrupted.